What is the reagent used in Clemmensen reduction?
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → $Zn-Hg/conc.\, HCl$
Core Concept
Clemmensen reduction converts aldehydes or ketones into hydrocarbons under strongly acidic conditions.
Detailed Explanation
Clemmensen reduction:
R–CO–R′ → R–CH₂–R′
The carbonyl group is reduced to –CH₂ group using:
Zinc amalgam (Zn–Hg) + concentrated HCl
Option 1: NH₂NH₂
Hydrazine is used in Wolff–Kishner reduction, not Clemmensen reduction.
Option 2: NaOCl
Sodium hypochlorite is an oxidizing agent.
Option 3: Zn–Hg / conc. HCl
This is the correct reagent combination used in Clemmensen reduction.
Option 4: NaHSO₃
Used for aldehyde purification, not reduction.